GB 8545-1987 Dimensional deviation and machining allowance of aluminum and aluminum alloy die forgings
Some standard content:
National Standard of the People's Republic of China
Dimensional tolerance and machining allowance of aluminium and aluminium alloy die forgings
Die forgings of aluminium and aluminium alloyDimensional tolerance and machining allowanceUDC 621. 741.7
:621.753.1
GB 8545-87
This standard applies to the dimensional tolerance and machining allowance of aluminium and aluminium alloy die forgings. The deviations marked on the die forging drawings or the deviations not marked shall generally comply with the provisions of this standard.
Classification of die forging dimensions
1.1 Dimensions related to die cavity: Structural dimensions of die forgings that are not affected by die misalignment and underpressure. As shown in Figure 1, "n" dimensions. 1.2 Dimensions unrelated to die cavity: Dimensions marked across the parting surface that are affected by die misalignment and underpressure. As shown in Figure 2, ", Yiren" dimensions.
【Direction
Figure 1 Dimensions related to the mold cavity n
Upward direction
Figure 2 Dimensions unrelated to the mold cavity
1.3 Oblique dimensions: dimensions that are inclined to the parting surface and unrelated to the mold cavity. 8±8. Dimensions as shown in Figure 7. 1.4 Process fillet: In order to improve the forging process, facilitate demolding during forging, and make it easier for metal to fill the mold cavity, and improve the internal and surface quality of the product, a coordinate-free process fillet is specified. 2 Deviation regulations and use
2.1 Cavity size deviation level
The cavity size deviation of die forgings is divided into two levels, A and B (see Table 1-A and Table 1-B). The deviation level should be indicated on the drawing according to the product requirements and after agreement between the supply and demand parties.
2.2 Dimension deviation related to the mold cavity
The dimensional deviation related to the mold cavity should comply with the provisions of Table【-A or Table 1-B. Approved by China National Nonferrous Metals Industry Corporation on December 21, 1987, implemented on December 1, 1988
Nominal Ni Shou
(n or scale)
7:-10 - 18
50-~80
80-- 120
120~180
>180-250
250~315
315-400
2400～500
>h00630
>630-800
With the mold
cavity, there is a difference in the card code
>800～1000
>1000-~ 1250
1250-- 1600
1600~~2000
2000~2500
>25003150
>3150 -4000
4000~5000
>5000--6300
GB 8545--87
Table 1·A
Cavity ruler small deviation A level
Product. cm
100|200400800≥12002000400060009000[1000100
8001200-2000.4000-.6000-.9000--11000l-22000- 200--400
No small deviation from the mold cavity,
+ 0. 5+ 0. 7
+0. 7+0. 8
.-- 0. 7
-2.4+2. 4
+- 1. 0+-1. 1
Plane parallelism is included in the allowable error range listed above, 10m
nominal size
mold type
cavity related
(n or)
small size deviation
18 -~ 30
230~50
80-- 120
>120~180
180-250
2250~315
2315-400
400-500
>500 -630
>630-~800
800--1000
≥1000~1250
1250~1600
21600~-2000
2000~2500
2500~3150
23150-1000
24000 5000
50006300
GB 8 5 4 5
Cavity size deviation Grade B
Table [-B
200400800120020004000600090021400050
-4001-800-1200-20004000--60009000-4000--22000～100200
No perfect size difference with the mold cavity.
Parallelism is included in the allowable deviation range of the series, 22
.91-1 2. 2
t2, 8
1. 8 -+ 2. 0
1-2. 6112. 9
-3. 4-3. 8
for example! : The cavity size deviation of the die forging is Class A, and its nominal size n is 8mm (the size related to the die cavity size is shown in Table 1A, and the allowable deviation is ±0.25mm107
GB8545
Example 2: The cavity size deviation of the die forging is Class B, and its nominal size is 8mm (the size related to the die cavity size is shown in Table 1-B, and the allowable deviation is ±8:5mm. 2.3 Dimension deviation unrelated to the die cavity
2.3.1 Calculation method of projection area when selecting die forging size deviation: 2.3.1.1 The projection area of a circular die forging is equal to the area of a circle. 2.3.1.2 The projection area of a non-circular die forging is calculated by calculating the projection area of one of its circumscribed simple sides (trapezoid, prism) , rectangle) and calculate by multiplication. As shown in Figure 3, the projection area is n×10: or calculated as a trapezoid. Figure 3 Schematic diagram of projection area
2.3.2 Dimension deviations unrelated to the mold cavity are directly found out from Table 1-A or Table 1-B according to the projection area of the die forging and the maximum dimension unrelated to the mold cavity. Other smaller "t\ dimensional deviations are the same as the "t general" dimensional deviations. For example: the projection area of the die forging is 25×10=250cm2, and t is 17mm. When the die forging cavity dimensional deviation is Class A, the intersection of the projection area 200~400cm2 and the nominal size 10~18mm in Table 1-A is found to have a deviation of +1.1 and 0.7. Then all dimensional deviations of this die forging that are unrelated to the mold cavity are ±lmm. When the dimension deviation of the die forging cavity is Class B, its deviation is found in Table 1-B as +1.1 and -0.8, then all the dimension deviations of this die forging that are not related to the die cavity are mm.
2.4 Misalignment
2.4.1 Misalignment refers to the misalignment of the corresponding parts of the die forging caused by the misalignment of the overall and local reference lines of the upper and lower dies. 2.4.2 The allowable misalignment is determined by the maximum nominal dimension perpendicular to the forging direction and shall comply with the provisions of Table 2. The allowable misalignment is not included in the dimensional deviation related to the die cavity, that is, the dimensional deviation related to the die cavity and the allowable misalignment are used separately. See Figures 4, 5 and 6.
Reference scale for allowable misalignment,
Figure 1 Misalignment Dimensional Diagram
Figure 5 Design Dimension
Figure 6 Actual Allowable Size
Maximum Nominal
Allowable Misalignment
GB8545
Allowable Misalignment
≥630~
≥1250~
>2000~
>3150~
For example: The maximum nominal size of the die forging perpendicular to the forging direction is 80mm, and the deviation is ±0.6mm. The misalignment is 0.5mm as found in Table 2. Then the actual maximum allowable size of the die forging is 80.6mm, the minimum size is 79.4mm, the maximum allowable misalignment is 0.5mm, and the minimum limit size is 78.9mm.
2.5 Oblique dimensional deviation
Oblique dimensional deviation is calculated according to the following formula: Oblique dimensional deviation - wall thickness offset + dimensional deviation unrelated to the mold cavity × tgβ Example: Figure 7, die forging projection area is 120cm, t is 10mm at most, the maximum nominal dimension n perpendicular to the forging direction is 50mm, wall thickness is 8mm, and die forging slope 8 is 10°. From Table 1-A (when the cavity dimensional deviation is Class B, it can be found from Table 1-B), the dimensional deviation unrelated to the mold cavity is 01.\mm, and from Table
2, the allowable offset is 0.3mm, and tg10°=0.1763. The oblique dimension deviation = ±0.3 + ±0. × 0.1763 + +08:0
The oblique dimension deviation of the die forging at this location is +0.45mm, and the actual maximum limit dimension of the die forging at this location is 8.45mm, and the minimum limit dimension is 7.61mm, see Figure 8.
Area A-120cmz
Figure 7 Design dimensions
2.61. Radius deviation of process fillet
Figure 8 Actual allowable dimensions
For any process fillet with a radius less than 50mm, the radius deviation shall comply with the provisions of Table 3. For process fillets greater than 50mm, the radius deviation shall be agreed upon by the supply and demand parties and indicated in the drawings. Table 3
Two corner radii
>2～4
Process fillet radius deviation
>6～8
>8～10
>10～20
>20~-35
>35~50
Note: When some important arc dimensions have deviation regulations but are easily confused with the process circle radius, the deviation should be indicated in the radius to distinguish them. 2.7
Die forging slope deviation
Die forging slope deviation shall comply with the provisions of Table 4
Die forging slope
Angle deviation
GB8545
Die forging slope code
Except forging slope deviation, angle deviation shall be calculated based on the short side dimension of the die forging angle and shall comply with the provisions of Table 5. 2.8.1
Table 5 Angle deviation
Short side dimension of angle, mm
>10~50
>50~120
120315
315~630
>630~1250
1250～2000
>2000-~3150
>3150~-6300
2.8.2 In addition to directly measuring the angle, the angle deviation of the die forging can also be converted into a ruler for measurement by calculation. The calculation method is as follows:
First, determine the length of the short side of the angle on the drawing, find the allowable angle deviation in Table 5, and then calculate as follows Figure 9 Schematic diagram of length dimension deviation calculation
In Figure 9: AC(b) is the long side of the angle, AB() is the short side of the angle, and B is perpendicular to AC. The distance when a=csinβ nominal angle is
m±rsinvi. The allowable length dimension obtained by converting the distance deviation into the allowable angle deviation is
2.9 The size deviation of the ear
The size deviation of the concave ear shall comply with the provisions of Table 1A or Table 1-B. Example: Figure 10, the distance between the die forgings (center distance) is 160mm. From Table 1-A (when the cavity size deviation is level 1, check from Table 11) When the set m is 160mm, the allowable deviation is ±0.9mm, and the distance between the convex ears (center distance) is 160: 0.9mm110
2.10 Warpage of die forgings
GB 8545-87
Distance between convex ears
The warpage of die forgings is determined according to the maximum nominal size of the die forging perpendicular to the forging direction. This deviation is used alone and shall comply with the provisions of Table 6.
Maximum nominal
Unaged
50~～
Residual burr of die forgings
>120～
Allowed warping
The maximum allowable residual burr of die forgings shall comply with the provisions of Table 7. >630~
Table 7 Maximum allowable residual burr
Maximum length dimension of die forging
Maximum allowable residual burr
≥>120~
>1250~
>630~
Note: ①This table is applicable to die forgings that use punching dies or milling machines, lathes and other mechanical processing methods to remove burrs. 2000
>1250~s
②The maximum allowable residual burr when the burrs are removed by metal band saw shall be indicated on the drawing after the supplier and the buyer reach an agreement. 2000-
3150~~
③In principle, all burrs with a thickness of less than 1mm generated during forging using combined dies, ejectors, etc. shall be removed. For small pieces or residual burrs that are difficult to remove, their length shall not exceed! mm. Peak and concave dimensions of ejector marks
The convex and concave marks caused by the ejector on the die forging shall not exceed the provisions of Table 8 and shall be used alone. Table 8
Projected area, cm*
Allowable ejection mark, mm0.4
Allowable peaks and depressions of ejection mark
>200>400
～800
～1200
≥1200
～2000
≥2000
≥6000
214000
Machining allowance on one side of die forgings
GB8545-87
The machining allowance on one side of die forgings shall comply with the provisions of Table 9: Table 9 Machining allowance on one side of die forgings
Maximum side length of die forgings||tt ||≥50～120
≥120～250
>250～~400
400～630
>630～1000
>1000～1250
>1250～1600
>1600～2000
>2000～2500
>2500～3150
>3150~～4000
>4000~5000
>50006300
Note: According to the needs of cutting processing, the allowance value in the table can be appropriately increased or decreased. Additional remarks:
This standard was drafted by Southwest Aluminum Processing Plant. The main drafters of this standard are Chen Nengxiu and Liu Fuhou. 12
Single business plus! Residue1
Table 5 Angle deviation
Short side of the angle, mm
>10~50
>50~120
120315
315~630
>630~1250
1250～2000
>2000-~3150
>3150~-6300||tt| |2.8.2 In addition to directly measuring the angle, the angle deviation of die forgings can also be measured by calculating the angle deviation into a ruler. The calculation method is as follows:
First, determine the short side length of the angle on the drawing, find the allowable angle deviation from Table 5, and then calculate as follows:
Figure 9 Schematic diagram of length dimension deviation calculation
In Figure 9: AC (b) is the long side of the angle, AB () is the short side of the angle, and B is perpendicular to AC. The distance when a=csinβ nominal angle is
m±rsinvi. The allowable length dimension obtained by converting the distance deviation into the allowable angle deviation is
2.9 Dimension deviation of ear
The dimensional deviation of the concave ear shall comply with the provisions of Table 1A or Table 1-B. For example: Figure 10, the distance between die forgings (center distance) is 160mm. From Table 1-A (when the cavity size deviation is level 1, check from Table 11) When the set m is 160mm, the allowable deviation is ±0.9mm, and the distance between the lugs (center distance) is 160: 0.9mm110
2.10 Warpage of die forgings
GB 8545-87
Distance between lugs
The warpage of die forgings is determined according to the maximum nominal size of the die forgings perpendicular to the forging direction. This deviation is used alone and shall comply with the provisions of Table 6.
Maximum nominal
Unaged
50~～
Residual burr of die forgings
>120～
Allowable warpage
The maximum residual burr allowed for die forgings shall comply with the provisions of Table 7. >630~
Table 7 Maximum allowable residual burr
Maximum length dimension of die forging
Maximum allowable residual burr
≥>120~
>1250~
>630~
Note: ①This table is applicable to die forgings that use punching dies or milling machines, lathes and other mechanical processing methods to remove burrs. 2000
>1250~s
②The maximum allowable residual burr when the burrs are removed by metal band saw shall be indicated on the drawing after the supplier and the buyer reach an agreement. 2000-
3150~~
③In principle, all burrs with a thickness of less than 1mm generated during forging using combined dies, ejectors, etc. shall be removed. For small pieces or residual burrs that are difficult to remove, their length shall not exceed! mm. Peak and concave dimensions of ejector marks
The convex and concave marks caused by the ejector on the die forging shall not exceed the provisions of Table 8 and shall be used alone. Table 8
Projected area, cm*
Allowable ejection mark, mm0.4
Allowable peaks and depressions of ejection mark
>200>400
～800
～1200
≥1200
～2000
≥2000
≥6000
214000
Machining allowance on one side of die forgings
GB8545-87
The machining allowance on one side of die forgings shall comply with the provisions of Table 9: Table 9 Machining allowance on one side of die forgings
Maximum side length of die forgings||tt ||≥50～120
≥120～250
>250～~400
400～630
>630～1000
>1000～1250
>1250～1600
>1600～2000
>2000～2500
>2500～3150
>3150~～4000
>4000~5000
>50006300
Note: According to the needs of cutting processing, the allowance value in the table can be appropriately increased or decreased. Additional remarks:
This standard was drafted by Southwest Aluminum Processing Plant. The main drafters of this standard are Chen Nengxiu and Liu Fuhou. 12
Single business plus! Residue1
Table 5 Angle deviation
Short side of the angle, mm
>10~50
>50~120bzxZ.net
120315
315~630
>630~1250
1250～2000
>2000-~3150
>3150~-6300||tt| |2.8.2 In addition to directly measuring the angle, the angle deviation of die forgings can also be measured by calculating the angle deviation into a ruler. The calculation method is as follows:
First, determine the short side length of the angle on the drawing, find the allowable angle deviation from Table 5, and then calculate as follows:
Figure 9 Schematic diagram of length dimension deviation calculation
In Figure 9: AC (b) is the long side of the angle, AB () is the short side of the angle, and B is perpendicular to AC. The distance when a=csinβ nominal angle is
m±rsinvi. The allowable length dimension obtained by converting the distance deviation into the allowable angle deviation is
2.9 Dimension deviation of ear
The dimensional deviation of the concave ear shall comply with the provisions of Table 1A or Table 1-B. For example: Figure 10, the distance between die forgings (center distance) is 160mm. From Table 1-A (when the cavity size deviation is level 1, check from Table 11) When the set m is 160mm, the allowable deviation is ±0.9mm, and the distance between the lugs (center distance) is 160: 0.9mm110
2.10 Warpage of die forgings
GB 8545-87
Distance between lugs
The warpage of die forgings is determined according to the maximum nominal size of the die forgings perpendicular to the forging direction. This deviation is used alone and shall comply with the provisions of Table 6.
Maximum nominal
Unaged
50~～
Residual burr of die forgings
>120～
Allowable warpage
The maximum residual burr allowed for die forgings shall comply with the provisions of Table 7. >630~
Table 7 Maximum allowable residual burr
Maximum length dimension of die forging
Maximum allowable residual burr
≥>120~
>1250~
>630~
Note: ①This table is applicable to die forgings that use punching dies or milling machines, lathes and other mechanical processing methods to remove burrs. 2000
>1250~s
②The maximum allowable residual burr when the burrs are removed by metal band saw shall be indicated on the drawing after the supplier and the buyer reach an agreement. 2000-
3150~~
③In principle, all burrs with a thickness of less than 1mm generated during forging using combined dies, ejectors, etc. shall be removed. For small pieces or residual burrs that are difficult to remove, their length shall not exceed! mm. Peak and concave dimensions of ejector marks
The convex and concave marks caused by the ejector on the die forging shall not exceed the provisions of Table 8 and shall be used alone. Table 8
Projected area, cm*
Allowable ejection mark, mm0.4
Allowable peaks and depressions of ejection mark
>200>400
～800
～1200
≥1200
～2000
≥2000
≥6000
214000
Machining allowance on one side of die forgings
GB8545-87
The machining allowance on one side of die forgings shall comply with the provisions of Table 9: Table 9 Machining allowance on one side of die forgings
Maximum side length of die forgings||tt ||≥50～120
≥120～250
>250～~400
400～630
>630～1000
>1000～1250
>1250～1600
>1600～2000
>2000～2500
>2500～3150
>3150~～4000
>4000~5000
>50006300
Note: According to the needs of cutting processing, the allowance value in the table can be appropriately increased or decreased. Additional remarks:
This standard was drafted by Southwest Aluminum Processing Plant. The main drafters of this standard are Chen Nengxiu and Liu Fuhou. 12
Single business plus! Residue4
Peaks and depressions of ejection marks are allowed
>200>400
～800
～1200
≥1200
～2000
≥2000
≥6000
214000
Machining allowance of single side of die forgings
GB8545-87
The machining allowance of single side of die forgings shall comply with the provisions of Table 9: Table 9 Machining allowance of single side of die forgings
Maximum side length of die forgings
≥50～120
≥1 20～250
>250～~400
400～630
>630～1000
>1000～1250
>1250～1600
>1600～2000
>2000～2500
>2500～3150
>3150~～4000
>4000~5000
>50006300
Note: According to the needs of cutting processing, the allowance value in the table can be appropriately increased or decreased. Additional remarks:
This standard was drafted by Southwest Aluminum Processing Plant. The main drafters of this standard are Chen Nengxiu and Liu Fuhou. 12
Single business plus! Surplus4
Peaks and depressions of ejection marks are allowed
>200>400
～800
～1200
≥1200
～2000
≥2000
≥6000
214000
Machining allowance of single side of die forgings
GB8545-87
The machining allowance of single side of die forgings shall comply with the provisions of Table 9: Table 9 Machining allowance of single side of die forgings
Maximum side length of die forgings
≥50～120
≥1 20～250
>250～~400
400～630
>630～1000
>1000～1250
>1250～1600
>1600～2000
>2000～2500
>2500～3150
>3150~～4000
>4000~5000
>50006300
Note: According to the needs of cutting processing, the allowance value in the table can be appropriately increased or decreased. Additional remarks:
This standard was drafted by Southwest Aluminum Processing Plant. The main drafters of this standard are Chen Nengxiu and Liu Fuhou. 12
Single business plus! Surplus
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.